Commonly known in the art are heat exchangers used in connection with an automotive vehicle for cooling the engine of the vehicle. The heat exchanger generally comprises an upper and lower manifold providing fluid reservoirs for the inlet and outlet of engine fluid to the heat exchanger, i.e., coolant. A plurality of coolant or fluid tubes extend between the manifolds providing fluid communication therebetween. These types of heat exchangers are liquid to air because liquid passes through the tanks and tubes while is air is passed external and between the tubes for cooling the fluid therein.
There are also air to air heat exchangers wherein air is passed within the tubes and air is passed externally thereover for heat exchange. This type of heat exchanger may be used in turbo charged engines wherein heat exchangers are routinely used for cooling compressed "charged" air from a turbo charger, on route to the cylinders for combustion.
Air fins are connected between fluid tubes for enhancing heat exchange between the external air and fluid tubes. The manifolds include a tank portion and header which are welded to one another. The core comprising the fluid tubes and air fins are soldered to the header. Generally, the core includes side support members connected on the sides thereof between the manifolds for providing additional support to the core.
U.S. Pat. No. 5,257,662, issued Nov. 2, 1993 in the name of Osborn illustrates a typical heat exchanger assembly including a pair of manifolds with headers and a core member connected between the headers. The core member commonly includes a plurality of fluid tubes extending between the tanks to provide fluid communicating therebetween, a plurality of fins connected to the fluid tubes for enhancing heat exchange, and structural side members connected between the tanks at the outer sides of the core member.
The heated fluid communicated between the manifolds and fluid tubes cause thermal expansion of the members. Ambient cooling air passes through and around the cooling fins and is disbursed about the fluid tubes, thereby allowing the fluid to release a majority of its thermal energy. The high amount of thermal energy released causes large thermal expansion of the fluid tubes, air fins, header and side support members. The large thermal expansion causes shear stresses between the tank portion and header and coolant tubes. Significant shear stresses are caused from the differences between the thermal expansions of the fluid tubes and the side support members. Over time, the shear stresses cause cracking and fatigue between the joints, resulting in leaks, lost pressure, and inefficient heat transfer characteristics. Therefore, it is desirable to reduce the shear stresses while allowing normal expansion to continue.
Various heat exchangers have utilized external components added to the heat exchangers, namely for mounting purposes. One such heat exchanger is disclosed in U.S. Pat. No. 2,506,051, issued May 2, 1950 in the name of Young. The heat exchanger of Young discloses use of a U-shaped bracket which is connected lengthwise along one of the tanks and extends and is connected to side support members extending along the core. This U-shaped member is utilized for mounting and supporting the heat exchanger. There is no disclosure of reducing the thermal stresses. The U-bracket prevents uninhibited thermal expansion of the manifolds and core.